Entering the Home
بِسْمِ اللَّهِ
Bismillah.
In the name of Allah.
What it means
Two words at the door decide what kind of house you are walking into. Mentioning Allah on entering keeps out company you cannot see, and it also resets your own state before you meet your family.
When and how
Say it as you come through the door, then greet the people of the house with salam. If nobody is home, the salam is still made, as the Companions used to greet themselves with peace on entering an empty house.
Its virtue
The Prophet ﷺ said that when a man mentions Allah as he enters his house and as he eats, Shaytan tells his followers there is no place to spend the night and no dinner here; but if he enters without mentioning Allah, Shaytan says we have found a place to sleep, reported in Sahih Muslim 2018.
Source
Muslim 2018sahih